Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

This website has been deprecated and exists as an archive only.

The TORTOISE website has been moved to https://tortoise.nibib.nih.gov.

For any information about TORTOISE generation V3.x.x, please refer to the new website.

1. Introduction to DIFF_PREP

Welcome to the DIFF_PREP software guide. In this document, details about the properties and usage of the software will be described.

Diffusion Tensor Imaging (DTI) is a Magnetic Resonance Imaging (MRI) modality, which allows in-vivo extraction of brain neural pathways. DTI requires a scan with at least 6 diffusion weighted volumes obtained with non-colinear diffusion gradient directions in addition to at least one diffusion-free T2W image (b0 image). Because of the patient/subject motion during the scan, the same voxels in different volumes do not generally correspond to exactly the same anatomical brain locations. Additionally, the common MR protocol used in DTI imaging, the Echo Planar Imaging protocol (EPI), introduces additional artifacts into the images.

The purpose of this software is to correct for all types of distortions induced during the DTI scan, including: motion distortions, eddy current distortions and B0 susceptibility induced EPI distortions. This will enable users to accomplish a correct tensor estimation and better fiber tracking.